Mind the Gap - How to Find and Fix Energy Leaks

If you have ever traveled on the London Underground (The Tube) you are likely familiar with the "Mind The Gap" warning, telling passengers that there is a gap you must step over when entering the train.


While waiting for the tube on a trip last May, it dawned on me that "mind the gap" is also particularly important for homeowners when it comes to sealing your house, where even the smallest gaps can result in drafts and wasted energy.

Fixing gaps is a very simple project, but a thorough approach can take a few hours, if not a good chunk of a day or weekend. Today we'll look at how to approach DIY home sealing and what you'll need to save money on your electric and gas bill.

The top 6 easy-to-fix list for gap/crack leaks in a home are:

1. Doors - around and under them
2. Windows - Gaps and cracks can form around the frame; windows may not seal when closed.
3. Plumbing penetrations
4. Wiring penetrations
5. Attic Hatches
6. Recessed lights

There are other areas as well, including furnace flue penetrations, vents, and a few problem areas in the attic itself. And once again, energy star has an excellent home sealing guide available for free.

Doors

Doors are often the single largest source of air infiltration in homes. It makes sense why - three sides totally open, the the hinge side must have enough space to move, really creating four gaps. And the tops and bottoms of doors are generally never looked at!

We've already talked about doors in previous posts, but I wanted to make sure that doors were briefly touched on again here to drive home the point.

The simplest way to improve a door seal is with a ratcheting strike plate. This was discussed in the sealing around the sides and tops of your door (in less than 30 seconds!) article.

The bottom of the door can be more problematic, but door sweeps (another 2 minute project) and adjustable thresholds can solve those problems.  I recently covered the topic of door thresholds in some depth.

Windows

Windows form a special challenge since they are meant to open and have a lot of wear and tear over their life.  Different window styles, such as double-hung, single-hung, sliders, and encasement all require different approaches for sealing.

In extreme climates, you should install double-pane or even triple-pane glass to provide extra insulation. 

For general sealing, weather stripping and caulking do the trick. Techniques for sealing windows were discussed in depth in The Three Problem Areas of Windows, with the three main problem areas being:

1. The "seams" where the window frame attaches to your interior wall.
2. The outside window frame "seams"
3. The seal that forms when the window is shut.

For older windows and extreme climates you may want to consider the good old fashioned plastic window insulator kit.

Plumbing and Wiring Penetrations

When a home is built, holes must be knocked out in drywall to allow for pipes and some wiring. Often times these holes are irregular and generally left open because a collar or fitting "hide" the holes.

A perfect example in my house was the motion sensor in the main living space. A 2" hole was made for a few wires, and the hole was left open because the sensor covered it. The sensor, however, did not for a tight fit, and was a major source of air and insect infiltration.

Depending on the size of the hole, use Great Stuff gap sealer for larger gaps or DAP Alex caulk for smaller gaps.

Your checklist for locating gaps should include:

1. Smoke detectors that are wired to you AC supply
2. Motion sensors or other wired alarm system sensors
3. Door bell fixtures
4. Pipes under sinks and behind toilets
5. Any point of entry for cable TV, satellite TV, etc.

If you are especially energetic and are considering adding insulation to your attic, be sure to first pull away existing insulation and seal around wire and plumbing penetrations in the attic.

Attic Hatch Sealing

Attic hatches can be terrible sources of air infiltration - so much so that I am planning an article dedicated to this subject. But for now, at least make sure you perform the following actions:

1. Add foam weather stripping around the perimeter of the hatch.  Hatches do not form a good seal by themselves.
2. Make sure the top of the hatch has insulation.  Either find batted fiberglass or use a couple layers of rigid foam board, and affix it to the top.

If you have an access door to the attic, consider getting an attic access door insulation. They generally come in a couple of different sizes.

Recessed Lights

Recessed lights (aka can lights) can also be terribly inefficient - not the lights themselves, but the fixtures.  Many fixtures simply get too hot and require that insulation must not touch the fixture.  As a result, special cans are created to create an inch or two barrier from the fixture, basically creating a circular "hole" in your insulation!

In recent years, new housings have come on the market allowing for totally sealed housings in which insulation may touch.   The "air tite" recessed housing is a good option for replacement, and comes in 4", 5" and 6" sizes.